Connecting an iMac to an HDTV

Appealing to my Apple geek friends (re: trying to hook up iMac to HDTV). I had it working last night, watched a show on Hulu without a hitch, turned off the tv, and went to bed. But this morning it won’t pick up the iMac signal anymore. Here’s what I’ve done:

1) Turned off TV
2) Turned off iMac
3) Plugged in HDMI cable into TV
4) Plugged in HDMI cable to RocketFish Mini DisplayPort to HDMI adapter
5) Turned TV back on
6) Turned iMac back on
7) Enabled TV’s HDMI port
8) Detect Displays

From here I know I’m supposed to see “Arrangements” and set the displays to “mirror,” which is what I did last night. I don’t have that option anymore today. I’ve tried every configuration of those steps above and can’t get a signal. The adapter is good. The cable is good. The TV is good. The inputs are good. What am I missing or not doing?